Washing Machine

ABSTRACT

A washing machine according to the present invention is configured such as to prevent intrusion of water into an ozone generator ( 42 ). That is, the washing machine is configured such that an introduction tube ( 43 ) extends downward from the ozone generator ( 42 ) to be connected to an air duct member ( 31 ). With this arrangement, even if water is condensed in the introduction tube ( 43 ) due to a temperature difference between the inside and the outside of the introduction tube ( 43 ), water droplets resulting from the water condensation do not intrude into the ozone generator ( 42 ), but fall down toward the air duct member ( 31 ) by their gravity. Further, even if water bubbles and detergent bubbles generated in an outer tub ( 7 ) during a washing process enter the introduction tube ( 43 ) and are broken to form water droplets, these water droplets, like the water drops resulting from the water condensation, do not intrude into the ozone generator ( 42 ), but fall down toward the air duct member ( 31 ) by their gravity.

TECHNICAL FIELD

The present invention relates to a washing machine.

BACKGROUND ART

Patent Document 1 proposes a prior art washing machine which is adaptedto supply ozone generated by an ozone generator into a washing tubthrough a connection tube for sterilization of laundry in the washingtub.

Patent Document 1: Japanese Unexamined Patent Publication No.2002-320792 DISCLOSURE OF THE INVENTION Problems to be Solved by theInvention

In the washing machine disclosed in Patent Document 1, the connectiontube horizontally extends from the ozone generator to be connected to awater supply case. Therefore, the ozone generated by the ozone generatorflows horizontally through the connection tube into the water supplycase, and then flows down through a duct to be supplied into the washingtub.

When a temperature difference occurs between the inside and the outsideof the connection tube, water is condensed in the connection tube. Ifwater droplets resulting from the water condensation adhere to theinterior surface of the connection tube, the water droplets are liableto flow horizontally through the connection tube into the ozonegenerator. If the water droplets intrude into the ozone generator andadhere to ozone generating electrodes of the ozone generator, the ozonegeneration efficiency, i.e., the laundry sterilization efficiency, isdisadvantageously reduced. Further, water bubbles and detergent bubblesgenerated in the washing tub during a washing process are liable toenter the connection tube through the duct and the water supply case. Ifthe bubbles are broken to form water droplets, these water droplets,like the water droplets resulting from the water condensation, areliable to intrude into the ozone generator.

Of course, it is desirable to position the aforementioned components ina compact and functionally efficient manner in the washing machine.

In view of the foregoing, it is a principal object of the presentinvention to provide a washing machine which is arranged to efficientlyclean laundry while preventing water from intruding into a gas generatorthat generates a gas effective for cleaning the laundry.

It is another object of the present invention to provide a washingmachine which includes a gas generator that generates a gas effectivefor cleaning laundry, and yet has a compact construction.

It is further another object of the present invention to provide awashing machine which is functionally efficient and yet has a simplifiedconstruction.

Means for Solving the Problems

According to an inventive aspect as set forth in claim 1, there isprovided a washing machine, which includes: a washing tub in whichlaundry is contained; an air duct through which air is introduced intothe washing tub; a gas generator which generates a gas effective forcleaning the laundry contained in the washing tub, the gas generatorbeing disposed above the washing tub; and a conduit through which thegas generated by the gas generator is introduced into the air duct, theconduit extending downward from the gas generator to be connected to theair duct.

According to an inventive aspect as set forth in claim 2, the gasgenerator includes a gas generating member having a gas generatingsurface that generates the gas effective for cleaning the laundry, andthe gas generating member is disposed with its gas generating surfacebeing perpendicular to a horizontal plane or inclined with respect tothe horizontal plane in the washing machine of claim 1.

According to an inventive aspect as set forth in claim 3, there isprovided a washing machine, which includes: a washing tub in whichlaundry is contained; an air duct through which air is introduced intothe washing tub; a gas generator which generates a gas effective forcleaning the laundry contained in the washing tub; a conduit throughwhich the gas generated by the gas generator is introduced into the airduct, the conduit communicating with the air duct and the gas generator;wherein the gas generator includes a gas generating member having a gasgenerating surface that generates the gas effective for cleaning thelaundry, and the gas generating member is disposed with its gasgenerating surface being perpendicular to a horizontal plane or inclinedwith respect to the horizontal plane.

According to an inventive aspect as set forth in claim 4, the washingmachine of any of claims 1 to 3 further includes an air blower whichsupplies the air into the washing tub from the air duct, the air blowerbeing disposed in the air duct, wherein the conduit is connected to aportion of the air duct upstream of the air blower with respect to anair flowing direction in which the air flows from the air duct to thewashing tub, and the air blower is disposed adjacent the gas generator.

According to an inventive aspect as set forth in claim 5, the washingmachine of claim 4 further includes: a first water supply unit whichsupplies water into the washing tub; a housing which accommodates thefirst water supply unit and the gas generator in adjacent relation andserves as an outer casing of the washing machine; and a wall provided inthe housing to isolate the first water supply unit and the gas generatorfrom each other.

According to an inventive aspect as set forth in claim 6, the housinghas a load/unload opening through which the laundry is loaded into andunloaded from the washing tub in the washing machine of claim 5. Thewashing machine of claim 5 further includes a door which covers anduncovers the load/unload opening, the door being provided in the housingin a slidable manner, wherein the gas generator is disposed in a doorsliding region of the housing in which the door is slid, and the firstwater supply unit is disposed outside the door sliding region in thehousing.

According to an inventive aspect as set forth in claim 7, the sliding ofthe door is guided by the wall in the washing machine of claim 6.

According to an inventive aspect as set forth in claim 8, the washingmachine of claim 6 or 7 further includes a second water supply unitwhich supplies water into the washing tub, wherein the air blower isdisposed between the second water supply unit and the gas generator.

According to an inventive aspect as set forth in claim 9, the secondwater supply unit is disposed outside the door sliding region in thehousing in the washing machine of claim 8.

According to an inventive aspect as set forth in claim 10, there isprovided a washing machine, which includes: a washing tub in whichlaundry is contained; a gas generator which generates a gas effectivefor cleaning the laundry contained in the washing tub; and a conduitthrough which the gas generated by the gas generator is introduced intothe washing tub; wherein the gas generator includes a gas generatingmember having a gas generating surface that generates the gas effectivefor cleaning the laundry, and the gas generating member is disposed withits gas generating surface being perpendicular to a horizontal plane orinclined with respect to the horizontal plane.

According to an inventive aspect of claim 11, the washing machine ofclaim 10 further includes: a first water supply unit which supplieswater into the washing tub; a housing which accommodates the first watersupply unit and the gas generator in adjacent relation and serves as anouter casing of the washing machine; and a wall provided in the housingto isolate the first water supply unit and the gas generator from eachother.

According to an inventive aspect as set forth in claim 12, the housinghas a load/unload opening through which the laundry is loaded into andunloaded from the washing tub in the washing machine of claim 11. Thewashing machine of claim 11 further includes a door which covers anduncovers the load/unload opening, the door being provided in the housingin a slidable manner, wherein the gas generator is disposed in a doorsliding region of the housing in which the door is slid, and the firstwater supply unit is disposed outside the door sliding region in thehousing.

According to an inventive aspect, of claim 13, the sliding of the dooris guided by the wall in the washing machine of claim 12.

EFFECTS OF THE INVENTION

According to the inventive aspect of claim 1, the gas generated by thegas generator is introduced into the air duct through the conduit, andcarried on the air flowing through the air duct to be supplied into thewashing tub, whereby the laundry contained in the washing tub iscleaned. The conduit extends downward from the gas generator to beconnected to the air duct. Therefore, even if water is condensed in theconduit due to a temperature difference occurring between the inside andthe outside of the conduit, water droplets resulting from the watercondensation do not intrude into the gas generator, but flow down towardthe air duct by their gravity. Even if water bubbles and detergentbubbles generated in the washing tub enter the conduit and are broken toform water droplets, these water droplets, like the water dropletsresulting from the water condensation, do not intrude into the gasgenerator, but flow down toward the air duct by their gravity. Since thegas generator is disposed above the washing tub, the intrusion of thewater droplets is more reliably prevented. This prevents water fromintruding into the gas generator, thereby ensuring efficient cleaning ofthe laundry.

According to the inventive aspect of claim 2, the gas generating surfaceis perpendicular to the horizontal plane, or is inclined with respect tothe horizontal plane. Therefore, even if the water droplets adhere tothe gas generating surface, the water droplets fall down by theirgravity. This prevents the water from intruding into the gas generatingsurface, thereby ensuring further efficient cleaning of the laundry.

According to the inventive aspect of claim 3, the gas generated by thegas generating surface of the gas generating member included in the gasgenerator is introduced into the air duct through the conduit, andcarried on the air flowing through the air duct to be supplied into thewashing tub, whereby the laundry contained in the washing tub iscleaned. The gas generating surface is perpendicular to the horizontalplane, or is inclined with respect to the horizontal plane. Therefore,even if the water droplets adhere to the gas generating surface, thewater droplets fall down by their gravity. This prevents the water fromintruding into the gas generating surface, thereby ensuring efficientcleaning of the laundry.

According to the inventive aspect of claim 4, the portion of the airduct upstream of the air blower with respect to the air flowingdirection in which the air flows from the air duct to the washing tubhas a negative internal pressure when the air blower disposed in the airduct is driven. The conduit is connected to the upstream portion of theair duct. Therefore, when the air blower is driven, the gas generated bythe gas generator is efficiently supplied into the air duct. Since theair blower is disposed adjacent the gas generator, the conduit has arelatively short length, and the gas generated by the gas generator isfurther efficiently supplied into the air duct. The relatively shortlength of the conduit reduces the temperature difference between theinside and the outside of the conduit, so that the water condensation isless liable to occur. This ensures further efficient cleaning of thelaundry.

According to the inventive aspect of claim 5, the wall isolates thefirst water supply unit and the gas generator from each other, so thatthe water from the first water supply unit is prevented from intrudinginto the gas generator. The first water supply unit and the gasgenerator are accommodated in adjacent relation in the housing, wherebythe washing machine has a compact construction.

According to the inventive aspect of claim 6, the first water supplyunit is disposed outside the door sliding region in the housing, so thatthe sliding of the door is unlikely to interfere with the water supplyfrom the first water supply unit. Thus, the first water supply unit hasa simplified construction as compared with a case in which the firstwater supply unit is disposed in the door sliding region. On the otherhand, the first water supply unit and the gas generator are isolatedfrom each other, because the gas generator is disposed in the doorsliding region in the housing. Thus, the water from the first watersupply unit is prevented from intruding into the gas generator, therebyensuring further efficient cleaning of the laundry.

According to the inventive aspect of claim 7, the wall functions toisolate the first water supply unit and the gas generator from eachother for prevention of the intrusion of the water into the gasgenerator as well as to guide the sliding of the door. Thus, the washingmachine has improved functionality, and yet has a simplifiedconstruction.

According to the inventive aspect of claim 8, the air blower isolatesthe second water supply unit and the gas generator from each other, sothat the water from the second water supply unit is prevented fromintruding into the gas generator.

According to the inventive aspect of claim 9, the second water supplyunit is disposed outside the door sliding region in the housing, so thatthe sliding of the door is unlikely to interfere with the water supplyfrom the second water supply unit. Therefore, the second water supplyunit has a simplified construction as compared with a case in which thesecond water supply unit is disposed in the door sliding region. On theother hand, the second water supply unit and the gas generator areisolated from each other, because the gas generator is disposed in thedoor sliding region in the housing. Thus, the water from the secondwater supply unit is prevented from intruding into the gas generator,thereby ensuring further efficient cleaning of the laundry.

According to the inventive aspect of claim 10, the gas generated by thegas generating surface of the gas generating member included in the gasgenerator is supplied into the washing tub through the conduit to cleanthe laundry in the washing tub. The gas generating surface isperpendicular to the horizontal plane, or is inclined with respect tothe horizontal plane. Therefore, even if water droplets adhere to thegas generating surface, the water droplets fall down by their gravity.This prevents the water from intruding into the gas generating surface,thereby ensuring efficient cleaning of the laundry.

According to the inventive aspect of claim 11, the wall isolates thefirst water supply unit and the gas generator from each other, so thatthe water from the first water supply unit is prevented from intrudinginto the gas generator. Further, the first water supply unit and the gasgenerator are accommodated in adjacent relation in the housing, wherebythe washing machine has a compact construction.

According to the inventive aspect of claim 12, the first water supplyunit is disposed outside the door sliding region in the housing, so thatthe sliding of the door is unlikely to interfere with the water supplyfrom the first water supply unit. Therefore, the first water supply unithas a simplified construction as compared with the case in which thefirst water supply unit is disposed in the door sliding region. On theother hand, the first water supply unit and the gas generator areisolated from each other, because the gas generator is disposed in thedoor sliding region in the housing. Thus, the water from the first watersupply unit is prevented from intruding into the gas generator, therebyensuring further efficient cleaning of the laundry.

According to the inventive aspect of claim 13, the wall functions toisolate the first water supply unit and the gas generator from eachother for prevention of the intrusion of the water into the gasgenerator as well as to guide the sliding of the door. Thus, the washingmachine has improved functionality, and yet has a simplifiedconstruction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a drum-type washing machine 1 accordingto one embodiment of the present invention.

FIG. 2 is a perspective view of major portions of the drum-type washingmachine 1 as seen from the rear upper right side.

FIG. 3 is a plan view of the major portions of the drum-type washingmachine 1 shown in FIG. 2.

FIG. 4 is a vertical sectional view of the drum-type washing machine 1taken along a lateral vertical plane and viewed from the front side.

FIG. 5A is a vertical sectional view of the drum-type washing machine 1taken along an anteroposterior vertical plane and viewed from the rightside with its opening 4 covered with an outer lid 2A.

FIG. 5B illustrates the drum-type washing machine of FIG. 5A with itsopening 4 uncovered with the outer lid 2A.

FIG. 6 is a perspective view illustrating an outer tub 7, a drying unit3 and peripheral components as seen from the rear upper right side.

FIG. 7 is a right side view illustrating the outer tub 7, the dryingunit 3 and the peripheral components shown in FIG. 6.

FIG. 8( a) is a perspective view of an ozone generator 42 as seen fromthe rear upper right side. FIG. 8( b) illustrates the ozone generator ofFIG. 8( a) with its case cap 64 detached. FIG. 8( c) illustrates anozone plate 51 taken out of the ozone generator of FIG. 8( b). FIG. 8(d) is a right side view of the ozone plate 51 of FIG. 8( c).

FIG. 9 is a block diagram showing the electrical construction of thedrum-type washing machine 1.

FIG. 10 is a flow chart showing a control sequence to be performed by acontrol section 40 when the drum-type washing machine 1 starts apredetermined washing process.

DESCRIPTION OF REFERENCE CHARACTERS

-   1: Drum-type washing machine-   2: Housing-   2A: Outer lid-   2B: Tap water supply valve-   2D: Bath water pump-   4: Opening-   7: Outer tub-   10: Drum-   16L: Partition wall-   31: Air duct member-   32: Fan-   33: Guide hood-   42: Ozone generator-   43: Introduction tube-   51: Ozone plate

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the drawings, embodiments of the present inventionwill hereinafter be described more specifically.

Construction of Drum-Type Washing Machine

FIG. 1 is a perspective view of a so-called top open drum-type washingmachine 1 which is an exemplary washing machine according to oneembodiment of the present invention. Description of the geometry of thedrum-type washing machine 1 is based on directional arrows shown on anupper right part of FIG. 1. FIG. 2 is a perspective view of majorportions of the drum-type washing machine 1 as seen from the rear upperright side. FIG. 3 is a plan view of the major portions of the drum-typewashing machine 1 shown in FIG. 2. FIG. 4 is a vertical sectional viewof the drum-type washing machine 1 taken along a lateral vertical planeand viewed from the front side. FIG. 5A is a vertical sectional view ofthe drum-type washing machine 1 taken along an anteroposterior verticalplane and viewed from the right side with its opening 4 covered with anouter lid 2A. FIG. 5B illustrates the drum-type washing machine of FIG.5A with its opening 4 uncovered with the outer lid 2A.

Housing

As shown in FIG. 1, the drum-type washing machine 1 includes a housing 2which defines an outer casing thereof. A top wall of the housing 2 hasan arc shape as seen in side section, and extends forwardly downwardfrom an anteroposteriorly generally middle position continuously to afront wall in a gradually curved manner. The housing 2 has an opening 4provided in an anteroposteriorly and laterally middle portion of the topwall thereof and serving as a load/unload opening through which laundryis loaded into and unloaded from the housing 2. The opening 4 has agenerally rectangular shape elongated anteroposteriorly, and is coveredand uncovered with an outer lid 2A (door). A pair of guide rails 21L,21R are provided on a portion of the top wall of the housing 2 formedwith the opening 4 as extending along a left edge and a right edge ofthe opening 4, and the outer lid 2A is anteroposteriorly slidable alongthe guide rails 21L, 21R.

The outer lid 2A is biased rearward in an opening uncovering directionby springs 38 (see FIG. 5A). During the operation of the drum-typewashing machine 1, an outer lid lock mechanism 49 (not shown in FIG. 1)provided in the housing 2 (e.g., on a front edge of the opening 4)engages the outer lid 2A to lock the outer lid 2A in a closed state.

A detergent container 8 which contains a detergent to be used forwashing the laundry is provided in a withdrawable manner in ananteroposteriorly generally middle position of the top wall of thehousing 2 on the left side of the opening 4. An operation/display panel6 for various settings and indications for the operation of thedrum-type washing machine 1 is provided in a front half portion of thetop wall of the housing 2 on the right side of the opening 4.

A lid opening button 6A to be operated to disengage the outer lid 2Afrom the aforementioned outer lid lock mechanism 49 (see FIG. 5A) foropening the outer lid 2A is provided on the operation/display panel 6.When the lid opening button 6A is pressed with the outer lid 2A beingclosed, the outer lid 2A is disengaged from the outer lid lockmechanism. Then, the outer lid 2A is slid rearward of the opening 4 by abiasing force of the springs 38 (see FIG. 5A), thereby uncovering theopening 4. A handle 2C is provided on a front edge of the outer lid 2A.For covering the opening 4 with the outer lid 2A when the opening 4 isuncovered, the outer lid 2A is slid forward over the opening 4 byholding the handle 2C. With the opening 4 being uncovered, the handle 2Cabuts against a rear edge of the opening 4 to prevent the outer lid 2Afrom sliding further rearward.

A housing portion 15 of a laterally elongated and generally rectangularbox shape having an open top as shown in FIG. 2 is provided unitarilywith the housing 2 inwardly of (or below) a rear portion of the top wallof the housing 2 on the rear side of the opening 4. The inside of thehousing portion 15 is partitioned into a first chamber 27, a secondchamber 28 and a third chamber 29 (as designated from the left side) bya partition wall 16L and a partition wall 16R which respectively haveupper edges continuous to the guide rails 21L and the guide rail 21R andeach serve as a wall. Since the partition walls 16L and 16R arecontinuous to the guide rails 21L and 21R, respectively, as describedabove, the sliding of the outer lid 2A (see FIG. 1) is guided by theguide rails 21L, 21R as well as the upper edges of the partition walls16L, 16R. As shown in FIGS. 5A and 5B, the outer lid 2A constantlycovers an upper portion of the second chamber 28 whether the opening 4is covered or uncovered. With the outer lid 2A being open as shown inFIG. 5B, the outer lid 2A except for a second chamber covering portionwhich covers the upper portion of the second chamber 28 is accommodatedalong a rear wall of the housing 2 below the housing portion 15.

As shown in FIG. 2, a tap water supply valve 2B (first water supplyunit) is disposed in the first chamber 27, and a bath water pump 2D(second water supply unit) is disposed in the third chamber 29. The tapwater supply valve 2B and the bath water pump 2D each have a watersupply port provided on an upper portion thereof. As shown in FIG. 1,the water supply ports are exposed at corresponding positions from thetop wall of the housing 2. Therefore, tap water can be supplied into thewashing machine by connecting the tap water supply valve 2B to externalwater supply equipment (e.g., a tap water faucet) via a water supplyhose not shown. Similarly, bath water can be supplied into the washingmachine by connecting a water supply hose (not shown) to the bath waterpump 2D with one end of the water supply hose being submerged in a bathtub. Further, the tap water supply valve 2B and the bath water pump 2Dcommunicate with the detergent container 8.

As described above, the second chamber 28, the first chamber 27 and thethird chamber 29 are isolated from each other by the partition wall 16Land the partition wall 16R as shown in FIG. 3, and the upper portion ofthe second chamber 28 is constantly covered with the outer lid 2A (seeFIG. 1). Therefore, even if the water happens to leak from either of thetap water supply valve 2B and the bath water pump 2D, there is nopossibility that leaking water flows into the second chamber 28.

Outer Tub and Drum

As shown in FIG. 4, an outer tub 7 is accommodated in the housing 2,more specifically, below the housing portion 15 (see FIG. 2). The outertub 7 includes a generally cylindrical peripheral wall 7A havingopposite end faces closed by end face walls (a left end face wall 7L anda right end face wall 7R), thereby having a liquid-tight and air-tightstructure. The outer tub 7 is disposed with its axis extending laterally(generally horizontally). A lower portion of the peripheral wall 7A ofthe outer tub 7 is supported by a plurality of dampers 5 (see FIG. 5A).

A drum 10 in which the laundry is contained is disposed in the outer tub7. The drum 10 includes a generally cylindrical peripheral wall 10Chaving opposite end faces closed by end face walls (a left end face wall10L and a right end face wall 10R), and is disposed with its axisextending laterally (generally horizontally). The outer tub 7 and thedrum 10 serve as a washing tub.

Rotation shafts 11L and 11R extending along the axis of the drum 10 areattached to the left and right end face walls 10L and 10R, respectively,of the drum 10. The rotation shafts 11L and 11R are rotatably attachedto the left and right end face walls 7L and 7R, respectively, of theouter tub 7. A drum-driving motor 12 of a so-called DD (direct drive)type is connected to the left rotation shaft 11L. By rotatively drivingthe motor 12, the drum 10 connected to the rotation shaft 11L is rotatedabout its axis at the same rotation speed as that of the motor. Threebaffles 10B which lift the laundry within the drum 10 during therotation of the drum 10 are provided on an interior surface of theperipheral wall 10C of the drum 10 in equiangularly spaced relation(e.g., in 120-degree spaced relation) along the inner periphery of theperipheral wall 10C as projecting inward and extending laterally.

As shown in FIG. 5A, the peripheral wall 10C of the drum 10 has anopening 22 through which the laundry is loaded into or unloaded from thedrum 10. The peripheral wall 7A of the outer tub 7 has an opening 23provided in opposed relation to the opening 4 of the housing 2.

The opening 22 of the drum 10 is covered and uncovered with a drum lid25 which is pivotal outward, and the opening 23 of the outer tub 7 iscovered and uncovered with an intermediate lid 26 which is pivotaloutward. With the outer lid 2A, the intermediate lid 26 and the drum lid25 being open, the laundry can be loaded into and unloaded from the drum10 through the opening 4 of the housing 2, the opening 23 of the outertub 7 and the opening 22 of the drum 10.

For loading or unloading the laundry into/from the drum 10, the drum lid25 is permitted to be opened only when the opening 22 of the drum 10 islocated in opposed relation to the opening 23 of the outer tub 7.Therefore, as shown in FIG. 4, a drum position fixing device 9 isattached to a lower portion of the left end face wall 7L of the outertub 7. The drum position fixing device 9 is adapted to engage the motor12 during the stop of the drum-type washing machine 1 so that therotational position of the drum 10 is fixed at a position at which theopening 22 of the drum 10 (see FIG. 5A) is opposed to the opening 23(see FIG. 5A) of the outer tub 7.

As shown in FIG. 5A, a water supply hose 17 communicating with theinside of the detergent container 8 is connected to a rear end portionof the peripheral wall 7A of the outer tub 7. By opening the tap watersupply valve 2B (see FIG. 1) or by driving the bath water pump 2D (seeFIG. 1), the tap water or the bath water (hereinafter referred togenerally as “water”) is supplied from the tap water supply valve 2B orthe bath water pump 2D (see FIG. 1) into the outer tub 7 through thedetergent container 8 (see FIG. 1) and the water supply hose 17. Thewater supply hose 17 is, for example, a flexible bellows hose, andfunctions to supply the water into the outer tub 7 as well as to preventvibrations occurring in the outer tub 7 during the rotation of the drum10 from being conducted to the housing 2. As shown in FIG. 2, a watersupply trap 24 is provided between the water supply hose 17 and thedetergent container 8. The water supply trap 24 temporarily retains thewater flowing from the detergent container 8 to the water supply hose 17to isolate the detergent container 8 and the water supply hose 17 fromeach other by the retained water, thereby preventing air communicationbetween the outer tub 7 and the outside.

As shown in FIG. 4, a drain port 19 is provided in a lower right portionof the peripheral wall 7A of the outer tub 7. A drain valve 18 isconnected to the drain port 19. By supplying water into the outer tub 7with the drain valve 18 being closed, the water is retained in the outertub 7. The drum 10 has a multiplicity of water communicationperforations 10A formed in substantially the entire peripheral wall 10Cthereof except for the opening 22 thereof. The water supplied into theouter tub 7 also flows into the drum 10 through the water communicationperforations 10A. By opening the drain valve 18, the water retained inthe outer tub 7 is drained outside the washing machine through the drainport 19 and a drain hose 20. One end of an overflow tube 37 (see FIG. 2)is connected to an intermediate portion of the drain hose 20. The otherend of the overflow tube 37 is connected to the right end face wall 7Rof the outer tub 7 at a predetermined height level. When the water isretained to the predetermined height level or higher, excess water isforcibly drained outside the washing machine through the overflow tube37 and the drain hose 20 (see FIG. 4). An overflow trap 45 is providedbetween the overflow tube 37 and the drain hose 20 (see FIG. 4). Theoverflow trap 45 temporarily retains water flowing through the overflowtube 37 and/or the drain hose 20 (see FIG. 4), thereby preventing aircommunication between the outer tub 7 and the outside through theoverflow tube 37 and/or the drain hose 20 by the retained water.

Drying Unit

As shown in FIG. 4, the drum-type washing machine 1 is capable ofperforming a drying process for drying the laundry, and a drying unit 3having a drying function is attached to an outer surface of the rightend face wall 7R of the outer tub 7.

FIG. 6 is a perspective view illustrating the outer tub 7, the dryingunit 3 and peripheral components as seen from the rear upper right side.FIG. 7 is a right side view illustrating the outer tub 7, the dryingunit 3 and the peripheral components shown in FIG. 6.

As shown in FIG. 6, the drying unit 3 includes an air duct member 31which sucks air from the outer tub 7 and guides the air upward, a fan 32serving as an air blower which supplies the air from the air duct member31 into the outer tub 7, a guide hood 33 which guides the air fed by thefan 32 into the outer tub 7, and a pair of heaters 34A, 34B (see FIG. 7)which heat the air to be fed into the outer tub 7. The air duct member31 and the guide hood 33 cooperatively function as an air duct forintroducing the air or airstream flowing therethrough into the outer tub7. The fan 32 is disposed in the air duct, more specifically, in anupper portion of the air duct member 31 with its generally upper halfportion accommodated in the second chamber 28 (see FIG. 3) of thehousing portion, and is rotatively driven by a blower motor 35. Theheaters 34A, 34B (see FIG. 7) are laterally juxtaposed in the guide hood33.

As shown in FIG. 4, an air outlet port 71 having a generally rectangularshape as seen from the front side is provided in a lower rear portion,e.g., a laterally generally middle portion, of the peripheral wall 7A ofthe outer tub 7. The air duct member 31 has a drain hole 30 (see FIG. 7)provided in a lower end portion thereof. The air outlet port 71 and thedrain hole 30 (see FIG. 7) are connected to each other through alaterally extending connection pipe 72, so that the inside of the airduct member 31 communicates with the inside of the outer tub 7. When thefan 32 (see FIG. 6) is rotatively driven, the air duct member 31 locatedupstream of the fan 32 with respect to an air flowing direction has anegative internal pressure. Therefore, air in the outer tub 7 is takeninto the drying unit 3 (air duct member 31) through the air outlet port71 and the connection pipe 72.

The outer tub 7 has an opening 7B provided in a center portion of theright end face wall 7R thereof, and the guide hood 33 (see FIG. 7) hasan air blowing port 41 (see FIG. 7) provided in an lower end portionthereof. Since the air blowing port 41 and the opening 7B (see FIG. 7)of the outer tub 7 communicate with each other, the inside of the guidehood 33 (see FIG. 7) communicates with the inside of the outer tub 7.Thus, as shown in FIG. 6, the air taken into the air duct member 31 outof the outer tub 7 is fed into the guide hood 33 by the fan 32 and thenblown into the outer tub 7 from the air blowing port 41, whereby the airis circulated in an air circulation passage defined by the air ductmember 31, the fan 32 and the guide hood 33 (i.e., the drying unit 3),and the outer tub 7. Further, as shown in FIG. 4, the drum 10 has anopening 10D provided in a center portion of the right end face wall 10Rthereof in opposed relation to the opening 7B of the outer tub 7, sothat the air circulating in the air circulation passage is also suppliedto the laundry in the drum 10.

During the drying process, for example, the air circulated in the aircirculation passage is heated by the heaters 34 and supplied into thedrum 10 from the air blowing port 41 (see FIG. 7) through the opening 7Bof the outer tub 7 and the opening 10D of the drum 10, while the drum 10is rotated. Thus, an operation such that the laundry is lifted by thebaffles 10B in the drum 10 and allowed to naturally fall from a certainheight is repeatedly performed. Therefore, the heated air is evenlyapplied to the laundry, whereby the laundry is properly dried.

It is possible to supply lower temperature air into the drum 10 byenergizing one of the heaters 34 (the heater 34A and the heater 34B)shown in FIG. 7 to drive the heaters 34 at a lower level (e.g., at about700 W) and to supply higher temperature air into the drum 10 byenergizing both of the heaters 34 to drive the heaters 34 at a higherlevel (e.g., at about 1400 W). It is also possible to supplyintermediate temperature air (heated at a level between the lower leveland the higher level) into the drum 10 by energizing both of the heaters34A, 34B and performing AC half-wave control on one of the heaters(controlling the driving of one of the heaters by utilizing AC in eachalternate half cycle) to drive the heaters 34 at an intermediate level(e.g., at about 1000 W).

As shown in FIG. 6, the air duct member 31 has the drain hole 30provided in the lower end portion thereof as described above, andincludes a first air duct member 311 and a second air duct member 312integrally provided, the first air duct member 311 extending upward fromthe lower end portion along the right end face wall 7R of the outer tub7, the second air duct member 312 being connected to an upper end of thefirst air duct member 311 and projecting leftward to be opposed to theperipheral wall 7A of the outer tub 7. The first air duct member 311 hasa planar shape having a laterally measured thickness that is smallerthan an anteroposteriorly measured thickness. On the other hand, thesecond air duct member 312 has a planar shape having ananteroposteriorly measured thickness that is smaller than a laterallymeasured thickness.

As shown in FIG. 7, the first air duct member 311 has a supply port 36provided in a left side wall thereof at a position slightly lower than ajunction between the first air duct member 311 and the second air ductmember 312. A supply pipe (not shown) is connected to an outer side ofthe supply port 36. By opening a supply valve 14 (not shown in FIG. 7)communicating with the supply pipe (not shown), cooling water (tapwater) is caused to flow at a predetermined flow rate (e.g., at about0.5 liter per minute) into the first air duct member 311 through thesupply pipe (not shown) and the supply port 36. During the dryingprocess, the cooling water is supplied into the first air duct member311 from the supply port 36 with the supply valve 14 being open. Thus,the first air duct member 311 functions as a heat exchanger for coolingair containing moisture (water vapor) emanated from the laundry tocondense the water vapor.

Ozone Generator

FIG. 8( a) is a perspective view of an ozone generator 42 (gasgenerator) as seen from the rear upper right side. FIG. 8( b)illustrates the ozone generator 42 of FIG. 8( a) with its case cap 64detached. FIG. 8( c) illustrates an ozone plate 51 (gas generatingmember) taken out of the ozone generator of FIG. 8( b). FIG. 8( d) is aright side view of the ozone plate 51 of FIG. 8( c).

As shown in FIG. 6, the drum-type washing machine 1 includes an ozonegenerator 42 which generates ozone as one example of a gas effective forcleaning the laundry, and an introduction tube 43 (conduit) whichpermits communication between the ozone generator 42 and the air ductmember 31 for introducing the ozone generated by the ozone generator 42into the air duct member 31. Exemplary processes for the cleaning of thelaundry with the use of the gas include washing, deodorization,sterilization and aromatization (for imparting the laundry withcomfortable fragrance).

As shown in FIG. 2, the ozone generator 42 is accommodated in the secondchamber 28 in the housing portion 15 of the housing 2. Morespecifically, the ozone generator 42 is disposed on the left side of thefan 32 in the second chamber 28 in adjacent relation to the tap watersupply valve 2B with the intervention of the partition wall 16L. Theozone generator 42 is located at a higher level than the outer tub 7,the air duct member 31 and the guide hood 33.

As shown in FIG. 8( a), the ozone generator 42 includes an ozone plate51 which actually generates the ozone, a casing 52 which accommodatesthe ozone plate 51, and a frame 53 to which the casing 52 is attachedfor fixing the casing 52 to the housing portion 15 of the housing 2.

As shown in FIG. 8( c), the ozone plate 51 is a laterally elongated thinplate. The ozone plate 51 has a rear surface which is perpendicular to ahorizontal plane or parallel to a vertical plane. The ozone plate 51includes a laterally elongated electrode 54A provided on a verticallygenerally middle portion thereof, and a laterally elongated electrode54B provided therein and having a slightly smaller size than the ozoneplate 51. The electrode 54A and the electrode 54B are disposed inanteroposteriorly spaced relation, and their longitudinally oppositeends are electrically connected to a power source board (not shown) viawirings 55. When a high voltage is applied between the electrode 54A andthe electrode 54B from the power source board (not shown) via thewirings 55, silent discharge occurs (as indicated by broken lines inFIG. 8( d)), whereby ozone is generated in air present around the rearsurface of the ozone plate 51.

As shown in FIG. 8( a), the casing 52 is divided into two portions,i.e., a front half portion and a rear half portion, which arerespectively designated as a case base 63 and a case cap 64. As shown inFIG. 8( b), the case base 63 is fixed to the frame 53.

With the case base 63 and the case cap 64 unified, as shown in FIG. 8(a), the casing 52 includes a main body 56, an air inlet portion 57disposed on the right side of the main body 56, and an ozone outletportion 58 disposed on the left side of the main body 56.

The main body 56 has an anteroposteriorly elongated, hollow andgenerally rectangular box shape, and has openings (not shown) providedin laterally opposite side faces thereof. The aforementioned ozone plate51 is accommodated in the main body 56. Further, three thread portions59 each formed with a screw hole are provided in laterally equidistantlyspaced relation on each of the vertically opposite faces of the fronthalf portion (the case base 63) of the main body 56. Insertion portions60 each formed with an insertion hole are provided on the rear halfportion (the case cap 64) of the main body 56 at positions correspondingto the thread portions 59. Screws 61 are respectively inserted throughthe insertion portions 60 and screwed into the thread portions 59,whereby the case base 63 and the case cap 64 are unified with the fronthalf portion and the rear half portion of the main body 56 beingcombined with each other. As shown in FIG. 8( b) an upper edge and alower edge of the ozone plate 51 accommodated in the main body 56 areeach fringed with a rubber packing 67. With the rubber packings 67pressed against the case base 63 and the case cap 64 thus unified, it ispossible to prevent the water from intruding into the ozone plate 51through a junction between the case base 63 and the case cap 64 and toprevent the ozone plate 51 from rattling.

As shown in FIG. 8( a), the air inlet portion 57 has a hollow andgenerally cubic shape, and has openings respectively provided invertically opposite faces, laterally opposite faces and a rear facethereof. Therefore, the inside of the air inlet portion 57 communicateswith the inside of the main body 56 through the right opening of themain body 56. A sponge filter 66 is fitted in the air inlet portion 57,so that external air is supplied to the ozone plate 51 in the main body56 after dust particles contained in the air are trapped by the spongefilter 66.

The ozone outlet portion 58 has a hollow cylindrical shape, and a rightend of the ozone outlet portion 58 is connected to the left opening ofthe main body 56 via a check valve 65. Thus, the inside of the ozoneoutlet portion 58 communicates with the inside of the main body 56.Since a left end of the ozone outlet portion 58 is connected to theintroduction tube 43, air containing the ozone generated by the ozoneplate 51 flows into the introduction tube 43 through the ozone outletportion 58. The check valve 65 permits the ozone and the air to flowinto the introduction tube 43 from the main body 56, but prevents theozone and the air from flowing back into the main body 56 from theintroduction tube 43.

The frame 53 has a hollow and generally rectangular box shape. Thewirings 55 for the ozone plate 51 and the power source board (not shown)are accommodated in the frame 53. The inside of the frame 53 is filledwith a flame-resistant and insulative urethane resin, thereby preventingthe wirings 55 and the power source board (not shown) from contactingwater and preventing electric leakage of the wirings 55 and the powersource board (not shown). Attachment stays 62 are provided on laterallyopposite ends of a bottom of the frame 53. As shown in FIG. 2, the ozonegenerator 42 is fixed in the second chamber 28 by fastening theattachment stays 62 to attachment portions (not shown) of the secondchamber 28 (see FIG. 2) of the housing portion 15 by screws or the like.

As shown in FIG. 6, one end of the introduction tube 43 is connected tothe ozone outlet portion 58 of the ozone generator 42. The other end ofthe introduction tube 43 is connected to a left wall of the second airduct member 312 of the air duct member 31, more specifically, to aportion of the second air duct member 312 adjacent to the fan 32,whereby the inside of the ozone generator 42 communicates with theinside of the air circulation passage including the air duct member 31,i.e., the drying unit 3. The introduction tube 43 is moderately bentdownward from the one end thereof, then bent in a middle portion thereofto extend further downward, and further bent to form a passage extendingto the other end thereof. Therefore, the air containing the ozonegenerated by the ozone generator 42 flows down through the introductiontube 43 to be supplied into the air duct member 31. When the fan 32 isrotatively driven, the air duct member 31 has a negative internalpressure as described above. This promotes the supply of the ozone tothe air duct member 31 from the ozone generator 42.

Washing Process in Drum-Type Washing Machine

FIG. 9 is a block diagram showing the electrical construction of thedrum-type washing machine 1.

As shown in FIG. 9, the operation of the drum-type washing machine 1 iscontrolled by a control section 40 including a microcomputer. Thecontrol section 40 further includes a CPU 41, a ROM 42, a RAM 43, atimer 44 and the like.

The operation/display section 6 (see FIG. 1) is connected to the controlsection 40 for input and output. Further, signals are inputted to thecontrol section 40 from a water level sensor (not shown) for detectingthe water level in the outer tub 7, a temperature sensor (not shown) fordetecting the temperature of air flowing out of the air outlet port 71of the outer tub 7 (see FIG. 4), and a door switch (not shown) fordetecting the opening and closing of the outer lid 2A.

The motor 12, the blower motor 35, the heaters 34, the tap water supplyvalve 2B, the bath water pump 2D, the supply valve 14, the drain valve18, the outer lid lock mechanism 49 and the ozone generator 42 areconnected to the control section 40 via a load drive section 48.

FIG. 10 is a flow chart showing a control sequence to be performed bythe control section 40 when the drum-type washing machine 1 starts apredetermined washing process.

Washing Step

When the operation of the drum-type washing machine 1 is started, asshown in FIG. 10, the control section 40 (see FIG. 9) first performs afirst washing step for a predetermined period (e.g., for six minutes)(Step S1). At the beginning of the first washing step, the water issupplied by opening the tap water supply valve 2B (see FIG. 9) or bydriving the bath water pump 2D (see FIG. 9). At this time, a detergentpreliminarily put in the detergent container 8 shown in FIG. 1 isdissolved in the supplied water, and the detergent-containing water isretained in the outer tub 7. After the completion of the supply of thewater into the outer tub 7 shown in FIG. 4, first intermittent control(e.g., 10-second ON and 3-second OFF) in which the motor 12 is rotatedat 45 rpm alternately in a forward direction and in a reverse directionwith a predetermined interval, second intermittent control (e.g.,10-second ON and 3-second OFF) in which the motor 12 is rotated at 30rpm alternately in the forward direction and in the reverse directionwith a predetermined interval, and third intermittent control (e.g.,10-second ON and 3-second OFF) in which the motor 12 is rotated at 60rpm alternately in the forward direction and in the reverse directionwith a predetermined interval are repeatedly performed in apredetermined sequence in the first washing step. In the firstintermittent control, an operation (so-called tumbling operation) suchthat the laundry present in the drum 10 is lifted by the baffles 10B andcaused to naturally fall from a certain height is repeatedly performedto achieve so-called beat-washing. In the second intermittent control,the laundry present on the bottom of the drum 10 is tumbled by thebaffles 10B to achieve so-called rub-washing. In the third intermittentcontrol, the drum 10 is rotated with the laundry kept adhering on theperipheral wall 10C of the drum 10. The water retained in the outer tub7 is absorbed by the laundry when the laundry comes to the bottom of theouter tub 7, and dirt of the laundry is removed together with the waterfrom the laundry when the water absorbed by the laundry is extractedfrom the laundry by a centrifugal force. At the end of the first washingstep, the water retained in the outer tub 7 is drained from the outertub 7, so that the laundry remains in the drum 10 with the water and thedetergent component contained therein.

After the completion of the first washing step, as shown in FIG. 10, thecontrol section 40 performs a second washing step for a predeterminedperiod (e.g., for 14 minutes) (Step S2). In the second washing step, asshown in FIG. 4, the drum 10 is rotated, while steam is supplied intothe outer tub 7 to warm the laundry by utilizing the drying unit 3.Thus, the water contained in the laundry is warmed, and a part of thelaundry containing the warmed water is rubbed with the other part of thelaundry or with the interior surface of the drum 10, or bumped againstthe interior surface of the drum 10 by the rotation of the drum 10. Asshown in FIG. 7, the steam is generated by atomizing the cooling watersupplied into the first air duct member 311 from the supply port 36 andheating the atomized water by the heaters 34 to evaporate the water. Inthe second washing step, there is no need to supply the water into theouter tub 7, so that the water consumption can be reduced as comparedwith a case in which the laundry is washed in water contained in theouter tub 7 by rotating the drum 10.

Intermediate Dehydrating Step

After the completion of the second washing step, as shown in FIG. 10,the control section 40 performs an intermediate dehydrating step (StepS3). In the intermediate dehydrating step, as shown in FIG. 4, the drum10 is rotated at a higher speed (e.g., at 300 to 1000 rpm), whereby thewater contained in the laundry is extracted from the laundry in the drum10, then spun out toward the outer tub 7 through the water communicationperforations 10A of the drum 10, and drained from the drain port 19. Inthe intermediate dehydrating step, the detergent component as well asthe water contained in the laundry is extracted from the laundry.

Rinsing Step

After the completion of the intermediate dehydrating step, as shown inFIG. 10, the control section 40 performs a rinsing step a plurality oftimes (e.g., twice) (Step S4). At the beginning of the rinsing step,water is supplied into the outer tub 7 by opening the tap water supplyvalve 2B (see FIG. 9) or by driving the bath water pump 2D (see FIG. 9),and then the drum 10 is rotated with a predetermined amount of waterbeing retained in the outer tub 7. Thus, the laundry is tumbled in thedrum 10. In the rinsing step, the detergent component remaining in thelaundry is diluted. At the end of the rinsing step, the water retainedin the outer tub 7 is drained from the outer tub 7. The final rinsingstep uses the tap water alone.

Final Dehydrating Step

After the completion of the rinsing step, as shown in FIG. 10, thecontrol section 40 performs a final dehydrating step (Step S5). In thefinal dehydrating step, as shown in FIG. 4, the drum 10 is rotated at ahigher speed (e.g., at 300 to 1000 rpm), whereby the water contained inthe laundry is extracted from the laundry in the drum 10 by acentrifugal force.

Drying Step

After the completion of the final dehydrating step, i.e., after thewater contained in the laundry is sufficiently removed from the laundry,as shown in FIG. 10, the control section 40 performs the drying step(Step S6).

In the drying step, as descried above and shown in FIG. 4, the controlsection 40 (see FIG. 9) rotates the drum 10 to tumble the laundry in thedrum 10, while feeding the air heated by the heaters 34 into the outertub 7 from the drying unit 3. Thus, the heated air is evenly applied tothe laundry in the drum 10, whereby the laundry is properly dried.

In the drying step, as shown in FIG. 7, the blower motor 35 is driven(e.g., at 4500 rpm), and the heaters 34 (34A, 34B) are energized to bedriven at the higher level. In the drying step, the air containingmoisture emanated from the laundry in the drum 10 flows into the airduct member 31 (first air duct member 311) from the outer tub 7 throughthe air outlet port 71 (see FIG. 4) and the connection pipe 72 (see FIG.4), then heated by the heaters 34, and fed again into the outer tub 7(drum 10). In the drying step, the supply valve 14 (see FIG. 9) isopened to supply the cooling water into the first air duct member 311from the supply port 36, whereby the moisture-containing air is cooledby the cooling water in the first air duct member 311 and the watercontained in the air is condensed through the heat exchange. Therefore,when the air flowing into the first air duct member 311 passes throughthe first air duct member 311, the water is removed from the air, whichis in turn heated by the heaters 34 and fed again into the outer tub 7(drum 10). The water is condensed on the interior surface of the firstair duct member 311 through the heat exchange, and flows on the interiorsurface. The water flowing on the interior surface of the first air ductmember 311 reaches the bottom of the air duct member 311, and flows outtogether with the cooling water from the drain hole 30. Then, as shownin FIG. 4, the water flows into the outer tub 7 through the connectionpipe 72 and the air outlet port 71, and is drained from the drain port19.

In the drying step, a so-called cool-down operation is performed for apredetermined period for cooling the dried laundry to a predeterminedtemperature by supplying unheated air into the drum 10. During thecool-down operation, as shown in FIG. 2, the control section 40 (seeFIG. 9) causes the ozone generator 42 to generate ozone. The generatedozone flows into the air duct member 31 through the introduction tube43, whereby the ozone is fed together with the air flowing through theaforementioned air circulation passage into the outer tub 7 (drum 10)and applied onto the laundry. Thus, a dirt component, an odor componentand a bacterial component remaining in the laundry are oxidized by thesupplied ozone, so that the laundry can be cleaned, deodorized andsterilized. During the supply of the ozone into the outer tub 7, asshown in FIG. 9, the tap water supply valve 2B, the supply valve 14 andthe drain valve 18 are kept closed, and the driving of the bath waterpump 2D is kept stopped by the control section 40. Further, as shown inFIG. 2, water is trapped in the water supply trap 24 when the water issupplied in the washing step, and trapped in the overflow trap 45 whenthe water is drained. Thus, the outer tub 7 is kept air-tight, therebyeliminating the possibility that the ozone leaks outside the washingmachine. During the supply of the ozone into the outer tub 7, as shownin FIG. 9, the control section 40 causes the outer lid lock mechanism 49to lock the outer lid 2A in the closed state (see FIG. 1) until all thesupplied ozone is consumed by an oxidation reaction and the ozoneconcentration is reduced to a level that exerts no influence on a humanbody.

Miscellaneous

Since the ozone easily penetrates into the dried laundry, a highercleaning effect can be provided by supplying the ozone to the drylaundry. Therefore, the cleaning of the laundry with the ozone may beperformed not only during the aforementioned drying step but also beforethe cleaning step. Where the laundry is cleaned with the ozone beforethe washing step, there is a possibility that no water is trapped in thewater supply trap 24 (see FIG. 2) and the overflow trap 45 (see FIG. 2).In order to keep the outer tub 7 air-tight as described above, thecontrol section 40 properly opens or closes the tap water supply valve2B, the supply valve 14 and the drain valve 18 and drives the bath waterpump 2D to retain the water in the water supply trap 24 and the overflowtrap 45. The ozone may be supplied before the washing step or during thedrying step, or before the washing step as well as during the dryingstep. As the ozone supply period increases, the cleaning of the laundryis promoted. The ozone cleaning function of the drum-type washingmachine 1 makes it possible to clean laundry that cannot be wetted withwater.

Effects

In the drum-type washing machine 1, as described above and shown in FIG.6, the ozone generated by the ozone generator 42 is introduced into theair duct member 31 through the introduction tube 43, and carried on theair flowing in the aforementioned air circulation passage including theair duct member 31 to be supplied into the outer tub 7, whereby thelaundry is cleaned with the ozone in the drum 10. The introduction tube43 extends downward from the ozone generator 42 to be connected to theair duct member 31. Therefore, even if water condensation occurs in theintroduction tube 43 due to the temperature difference between theinside and the outside of the introduction tube 43, water dropletsresulting from the water condensation do not intrude into the ozonegenerator 42, but fall down toward the air duct member 31 by theirgravity. Further, even if water bubbles and detergent bubbles generatedin the outer tub 7 during the washing process enter the introductiontube 43 and are broken to form water droplets, these water droplets,like the water droplets resulting from the water condensation, do notintrude into the ozone generator 42, but fall down toward the air ductmember 31 by their gravity. Since the ozone generator 42 is disposedabove the outer tub 7, the intrusion of the water droplets is morereliably prevented. This prevents the water from intruding into theozone generator 42, thereby ensuring efficient cleaning of the laundry.

As shown in FIG. 8, the ozone plate 51 which actually generates ozone inthe ozone generator 42 is disposed with its rear surface (ozonegenerating surface) being perpendicular to the horizontal plane.Therefore, even if the water droplets adhere to the rear surface, thewater droplets fall down by their gravity. This prevents the water fromintruding into the rear surface of the ozone plate 51, thereby ensuringfurther efficient cleaning of the laundry. The rear surface may beinclined with respect to the horizontal plane, as long as it is possibleto cause the adhering water droplets to fall down.

As shown in FIG. 6, when the fan 32 disposed in the aforementioned airduct (including the air duct member 31 and the guide hood 33) is driven,the portion of the air duct upstream of the fan 32 with respect to theair flowing direction in which the air flows from the air duct to theouter tub 7, i.e., the air duct member 31, has a negative internalpressure. Since the introduction tube 43 is connected to the air ductmember 31, the ozone generated by the ozone generator 42 is efficientlysupplied into the air duct member 31 when the fan 32 is driven. Further,the fan 32 is disposed adjacent the ozone generator 42, so that theintroduction tube 43 has a relatively short length. Thus, the gasgenerated by the ozone generator 42 can be more efficiently suppliedinto the air duct member 31. Further, the relatively short length of theintroduction tube 43 reduces the temperature difference between theinside and the outside of the introduction tube 43, so that the watercondensation is less liable to occur. Thus, the drum-type washingmachine 1 is capable of efficiently cleaning of the laundry, and yet hasa compact construction.

As shown in FIG. 3, the ozone generator 42 accommodated in the secondchamber 28 is isolated from the tap water supply valve 2B accommodatedin the first chamber 27 by the partition wall 16L in the housing portion15 of the housing 2, so that the water from the tap water supply valve2B is prevented from intruding into the ozone generator 42. Since thetap water supply valve 2B and the ozone generator 42 are disposed inadjacent relation, the drum-type washing machine 1 has a compactconstruction. As shown in FIG. 2, the upper edge of the partition wall16L is continuous to the guide rail 21L, so that the sliding of theouter tub 2A (see FIG. 1) is guided by the guide rail 21L as well as theupper edge of the partition wall 16L. Therefore, the partition wall 16Lfunctions to isolate the tap water supply valve 2B and the ozonegenerator 42 from each other for prevention of the intrusion of thewater into the ozone generator 42 as well as to guide the sliding of theouter tub 2A. Thus, the drum-type washing machine 1 has improvedfunctionality, and yet has a simplified construction.

As shown in FIG. 3, the ozone generator 42 is disposed on the left sideof the fan 32 in adjacent relation to the fan 32 in the second chamber28. That is, the fan 32 is disposed on a side of the ozone generator 42opposite from the tap water supply valve 2B in adjacent relation to theozone generator 42. Further, the fan 32 is disposed between the bathwater pump 2D and the ozone generator 42. Therefore, the fan 32 isolatesthe bath water pump 2D and the ozone generator 42 from each other, sothat water from the bath water pump 2D is prevented from intruding intothe ozone generator 42. Since the tap water supply valve 2B, the ozonegenerator 42, the fan 32 and the bath water pump 2D are located in thisorder, the drum-type washing machine 1 has a compact construction.

As shown in FIGS. 5A and 5B, the outer lid 2A constantly covers theupper portion of the second chamber 28 whether the opening 4 is coveredor uncovered. Therefore, the ozone generator 42 is disposed in the outerlid sliding region in which the outer lid 2A is slid. On the other hand,the first chamber 27 which accommodates the tap water supply valve 2Band the third chamber 29 which accommodates the bath water pump 2D aredisposed outside the outer lid sliding region as shown in FIG. 3.Therefore, the tap water supply valve 2B, the bath water pump 2D and theozone generator 42 are isolated from each other, so that the water fromthe tap water supply valve 2B and the bath water pump 2D is preventedfrom intruding into the ozone generator 42. This ensures furtherefficient cleaning of the laundry. In addition, the sliding of the outerlid 2A is unlikely to interfere with the water supply to the outer tub 7from the tap water supply valve 2B and the bath water pump 2D. Further,the washing machine has a simplified construction as compared with acase in which the tap water supply valve 2B and the bath water pump 2Dare disposed in the outer lid sliding region.

Modifications

The present invention is not limited to the embodiments described above,but various modifications may be made within the purviews of theappended claims.

The axis of the drum 10 is not necessarily required to extend laterally,but may extend anteroposteriorly. In this case, the direction of theaxis of the drum is not limited to a generally horizontal direction, butthe axis of the drum may be inclined at an angle smaller than apredetermined angle (e.g., up to about 30 degrees) with respect to thehorizontal direction. Further, the axis of the drum may extendvertically.

The drum-type washing machine 1 is of a top open type in which the upperlid 2A is provided on the top wall of the housing 2, but may be of aso-called front open type in which a lid is provided on the front wall.

In the embodiments described above, the drum-type washing machine 1having the drying function has been described as an example of theinventive drum-type washing machine. The present invention is applicableto a drum-type washing machine having no drying function and to avortex-type washing machine employing a pulsator. The washing machinehaving no drying function may be configured such that the ozonegenerated by the ozone generator 42 (gas generator) is supplied directlyto the washing tub.

The ozone generator 42 adapted to generate the ozone which is effectivefor the cleaning, the deodorization and the sterilization of the laundryis used as the gas generator, but the gas generator may be adapted togenerate a gas which is effective, for example, for aromatization of thelaundry.

1. A washing machine comprising: a washing tub in which laundry iscontained; an air duct through which air is introduced into the washingtub; a gas generator which generates a gas effective for cleaning thelaundry contained in the washing tub, the gas generator being disposedabove the washing tub; and a conduit through which the gas generated bythe gas generator is introduced into the air duct, the conduit extendingdownward from the gas generator to be connected to the air duct.
 2. Awashing machine as set forth in claim 1, wherein the gas generatorincludes a gas generating member having a gas generating surface thatgenerates the gas effective for cleaning the laundry, wherein the gasgenerating member is disposed with its gas generating surface beingperpendicular to a horizontal plane or inclined with respect to thehorizontal plane.
 3. A washing machine comprising: a washing tub inwhich laundry is contained; an air duct through which air is introducedinto the washing tub; a gas generator which generates a gas effectivefor cleaning the laundry contained in the washing tub, a conduit throughwhich the gas generated by the gas generator is introduced into the airduct, the conduit communicating with the air duct and the gas generator;wherein the gas generator includes a gas generating member having a gasgenerating surface that generates the gas effective for cleaning thelaundry; wherein the gas generating member is disposed with its gasgenerating surface being perpendicular to a horizontal plane or inclinedwith respect to the horizontal plane.
 4. A washing machine as set forthin claim 1, further comprising: an air blower which supplies the airinto the washing tub from the air duct, the air blower being disposed inthe air duct; wherein the conduit is connected to a portion of the airduct upstream of the air blower with respect to an air flowing directionin which the air flows from the air duct to the washing tub; wherein theair blower is disposed adjacent the gas generator.
 5. A washing machineas set forth in claim 4, further comprising: a first water supply unitwhich supplies water into the washing tub; a housing which accommodatesthe first water supply unit and the gas generator in adjacent relationand serves as an outer casing of the washing machine; and a wallprovided in the housing to isolate the first water supply unit and thegas generator from each other.
 6. A washing machine as set forth inclaim 5, wherein the housing has a load/unload opening through which thelaundry is loaded into and unloaded from the washing tub; the washingmachine further comprising: a door which covers and uncovers theload/unload opening, the door being provided in the housing in aslidable manner; wherein the gas generator is disposed in a door slidingregion of the housing in which the door is slid; wherein the first watersupply unit is disposed outside the door sliding region in the housing.7. A washing machine as set forth in claim 6, wherein the sliding of thedoor is guided by the wall.
 8. A washing machine as set forth in claim6, further comprising: a second water supply unit which supplies waterinto the washing tub; wherein the air blower is disposed between thesecond water supply unit and the gas generator.
 9. A washing machine asset forth in claim 8, wherein the second water supply unit is disposedoutside the door sliding region in the housing.
 10. A washing machinecomprising: a washing tub in which laundry is contained; a gas generatorwhich generates a gas effective for cleaning the laundry contained inthe washing tub; and a conduit through which the gas generated by thegas generator is introduced into the washing tub; wherein the gasgenerator includes a gas generating member having a gas generatingsurface that generates the gas effective for cleaning the laundry,wherein the gas generating member is disposed with its gas generatingsurface being perpendicular to a horizontal plane or inclined withrespect to the horizontal plane.
 11. A washing machine as set forth inclaim 10, further comprising: a first water supply unit which supplieswater into the washing tub; a housing which accommodates the first watersupply unit and the gas generator in adjacent relation and serves as anouter casing of the washing machine; and a wall provided in the housingto isolate the first water supply unit and the gas generator from eachother.
 12. A washing machine as set forth in claim 11, wherein thehousing has a load/unload opening through which the laundry is loadedinto and unloaded from the washing tub; the washing machine furthercomprising: a door which covers and uncovers the load/unload opening,the door being provided in the housing in a slidable manner; wherein thegas generator is disposed in a door sliding region of the housing inwhich the door is slid, wherein the first water supply unit is disposedoutside the door sliding region in the housing.
 13. A washing machine asset forth in claim 12, wherein the sliding of the door is guided by thewall.
 14. A washing machine as set forth in claim 2, further comprising:an air blower which supplies the air into the washing tub from the airduct, the air blower being disposed in the air duct; wherein the conduitis connected to a portion of the air duct upstream of the air blowerwith respect to an air flowing direction in which the air flows from theair duct to the washing tub; wherein the air blower is disposed adjacentthe gas generator.
 15. A washing machine as set forth in claim 3,further comprising: an air blower which supplies the air into thewashing tub from the air duct, the air blower being disposed in the airduct; wherein the conduit is connected to a portion of the air ductupstream of the air blower with respect to an air flowing direction inwhich the air flows from the air duct to the washing tub; wherein theair blower is disposed adjacent the gas generator.
 16. A washing machineas set forth in claim 15, further comprising: a first water supply unitwhich supplies water into the washing tub; a housing which accommodatesthe first water supply unit and the gas generator in adjacent relationand serves as an outer casing of the washing machine; and a wallprovided in the housing to isolate the first water supply unit and thegas generator from each other.
 17. A washing machine as set forth inclaim 14, further comprising: a first water supply unit which supplieswater into the washing tub; a housing which accommodates the first watersupply unit and the gas generator in adjacent relation and serves as anouter casing of the washing machine; and a wall provided in the housingto isolate the first water supply unit and the gas generator from eachother.
 18. A washing machine as set forth in claim 17, wherein thehousing has a load/unload opening through which the laundry is loadedinto and unloaded from the washing tub; the washing machine furthercomprising: a door which covers and uncovers the load/unload opening,the door being provided in the housing in a slidable manner; wherein thegas generator is disposed in a door sliding region of the housing inwhich the door is slid; wherein the first water supply unit is disposedoutside the door sliding region in the housing.
 19. A washing machine asset forth in claim 16, wherein the housing has a load/unload openingthrough which the laundry is loaded into and unloaded from the washingtub; the washing machine further comprising: a door which covers anduncovers the load/unload opening, the door being provided in the housingin a slidable manner; wherein the gas generator is disposed in a doorsliding region of the housing in which the door is slid; wherein thefirst water supply unit is disposed outside the door sliding region inthe housing.
 20. A washing machine as set forth in claim 7, furthercomprising: a second water supply unit which supplies water into thewashing tub; wherein the air blower is disposed between the second watersupply unit and the gas generator.